1. Field of the Invention
The present invention relates to apparatus for automatically handling a multiplicity of randomly associated hematological samples, and, more particularly, concerns apparatus for automatically mixing, resuspending and aspirating pre-prepped blood samples and transferring such resuspended samples to other operably associated cytometric apparatus.
2. Description of the Prior Art
U.S. Pat. No. 4,845,025, entitled "Biological Sample Mixing Apparatus and Method" relates to automatic biological sample mixing apparatus for use in flow cytometric apparatus, wherein a sample container is secured loosely at its top by means of a multi-reagent dispensing head; and the container is mounted at its bottom on a resilient support disposed on an elliptically rotatable member, to cause reagents introduced into the container to be thoroughly mixed with a sample in the container in a fast, efficient, gentle, and accurately repeatable manner.
A recent improvement upon the COULTER.RTM. Q-Prep and also protected by U.S. Pat. No. 4,845,025 is the COULTER.RTM. Multi-Q-Prep which consists of a 32-tube capacity removable carousel, sensor and sequencing devices, a reagent delivery system, mixer and timing devices. An indexing base moves the carousel in counterclockwise direction to a home position and during sequential sample processing. A tube detector/lifter senses the presence of a sample containing tube in the carousel at mixing position and lifts it up into the dispensing head. A retractable dispensing head adds precise amounts of reagents to the sample. A vortexer/mixer mixes reagents into the sample.
Such prior art, while capable of efficiently and accurately mixing various reagents with the sample, requires that the mixed or pre-prepped sample be removed manually from the mixing apparatus (the COULTER Q-Prep or Multi-Q-Prep) and also the tube and transferred manually to a sample analyzer, for example, a flow cytometer such as the COULTER.RTM. EPICS.RTM. Profile or XL. Both apparatuses utilize pressure syringes to provide fluid movement. The Q-Prep apparatus does not use bar codes or a bar code reader, inasmuch as it operates on a single, operator manually delivered sample container, one at a time. The Multi-Q-Prep carousel has its 32 tube positions bar coded for sample I.D. Also, these two patented apparatuses rotate in one direction only; and one utilizes a cam and lever operated drive and the other has a notched belt for container rotation and reagent mixing. Vacuum devices and pumps, as used in the apparatus, are relatively expensive, require continuous care and maintenance and the cost is sometimes considerable to the point where it might become prohibitive for small laboratories or medical offices.